perc3: 1: importing containers; 2: snapshots

jason andrade jason at rtfmconsult.com
Sat Oct 11 22:17:00 CDT 2003


On Sat, 11 Oct 2003, Matthew Burgoon wrote:

> I've got a couple of questions, and as I'm now beating my head against
> the wall in frustration, I am now sending email to this list begging for
> help and ideas. I have a poweredge 2450 with a Perc3/Si running firmware
> build #2951.

you may want to consider an upgrade - i think the latest rev is build #3571
(aka 2.7-1)

> Here's my basic need: I need to take a snapshot of a live file system
> that is sitting on top of a mirrored container. Assume I cannot reboot
> the machine, remount the file system read only, let alone unmount the
> disk at all, and doing a tar isn't an option. It must be a real-time
> snapshot.

i believe this is what people have been installing LVM for as it is meant
to allow you to do FS snapshots.  of course this probably doesn't help
you in your current config..

> So, I thought perhaps if I just yank the disk, put it into another 2450
> with a Perc3/Si controller, I could just import what it would think is a
> degraded mirror. But I cannot figure out how to get it to do this, and I
> would hope this is possible. Anyone know? Nothing shows up in disk show
> partition/space, container list, nada.

enclosure prepare slot 0 <number of slot>

you should then be able to take this to another machine.

> If anyone could provide me with some commands, ideas, facts, suggestions
> or a lot of beer so the problem magically goes away, it would be greatly
> appreciated.

the long term solution is perhaps to look at LVM and it may do what you
want in a more graceful manner.

the main problem that i see is snapshotting files with open handles.  otherwise
i would have recommended looking at rsync (have you considered this?).  just
rsync to another disk at regular internals and just before you need a snapshot
runn rsync again - it should pickup only the changes and finish in a few seconds.

regards,

-jason




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